Techniques for improving the radiation hardness of substrates have included implanting atoms or ions, such as silicon, into a buried oxide in the substrate. This serves to create electron traps/recombination centers in the buried oxide. See, for example, U.S. Pat. No. 5,795,813 issued to Hughes et al., entitled “Radiation-Hardening of SOT by Ion Implantation into the buried oxide layer” (hereinafter “U.S. Pat. No. 5,795,813”).
With techniques such as those described in U.S. Pat. No. 5,795,813, care must be taken not to damage the active layer of the wafer during the implantation process. Damage can be controlled by regulating the dose. However, that leaves only a limited window between doses which are too high and will overly damage the active layer and those that are too low and will not be effective for radiation hardening.
Accordingly, improved techniques for producing radiation hardened substrates would be desirable.